Twinturbos are generally not seen as better than 1 turbo, unless on cars like Mitibushi 3000GT (GTO in America?)or Toyota Supra, where a V engine or 6 cylinders makes it more efficient to have 2 single ones looking after 3 cylinders each.



Twincharging is using a supercharger and a turbo on the same engine. When its done and it works its amazing, but so far only 2 manufacturers have dared touch it in 20 years, and one of those was a breakdown waiting to happen.